In modern internal combustion engines, devices for variably adjusting the valve timing of gas exchange valves are used, in order for it to be possible to variably configure the phase relation between the crankshaft and the camshaft in a defined angular range, between a maximum early and a maximum late position. For this purpose, the device is integrated into a drive train, via which torque is transmitted from the crankshaft to the camshaft. Said drive train can be realized, for example, as a belt, chain or gearwheel drive.
A device of this type is known, for example, from U.S. Pat. No. 5,901,674 A. The device comprises an output element which is arranged rotatably with respect to a drive element, the drive element being in a drive connection with the crankshaft and the output element being connected fixedly to the camshaft so as to rotate with it. The device is delimited in the axial direction by in each case one side cover. The output element, the drive element and the two side covers delimit five pressure spaces, each of the pressure spaces being divided by means of a vane into two pressure chambers which act counter to one another. As a result of the feeding of pressure medium to or the discharge of pressure medium from the pressure chambers, the vanes are displaced within the pressure spaces in the circumferential direction of the device, as a result of which a targeted rotation of the output element with respect to the drive element and therefore of the camshaft with respect to the crankshaft is brought about. A plurality of axial pressure medium lines which are configured as holes are provided within the camshaft. Pressure medium can be fed to the pressure chambers via said pressure medium lines. Each of the pressure medium lines which are formed within the camshaft opens on the axial side face of the camshaft into a corresponding pressure medium line which are configured as holes in the output element and communicate with at least one of the pressure chambers. Here, the opening of one pressure medium line lies directly opposite the opening of the second pressure medium line in the axial direction.
It is disadvantageous in this embodiment that it has to be ensured during the mounting of the output element on the camshaft that the holes of the output element are aligned with the holes of the camshaft. Deviations of the orientation in the circumferential direction lead to alignment errors, as a result of which a throttling point is produced at the interface between the camshaft and the output element. This impairs the adjusting speed and the dynamics of the phase adjustment. In the case of excessively large deviations, the alignment error can also lead to the complete non-functionality of the device.
The orientation of the components with respect to one another is usually ensured by press-in pins. To this end, a hole is provided both in the camshaft and in the output element. During the mounting of the output element on the camshaft, a pin is pressed into the hole of the output element, which pin is subsequently likewise fixed nonpositively in the hole of the camshaft. However, this is a complex and expensive manufacturing process with multiple stages. In addition, tolerance deviations of the openings with respect to one another cannot be compensated for on account of the double press fit of the pin. As a result, throttling effects can occur at the interface between the output element and the camshaft despite the orientation of the components with respect to one another.